Interviewed after the final race at Silverstone, Bushell did say that he'd like to get back in the BTCC again but (if I recall correctly) it would be hard work to get there. He'll definitely be on the radar for a few teams, I reckon, but he'll have to put some graft in to get the sponsors.
He's also, all being well, going to be a dad around BTCC media day next year, so he's going to be busy with that too